Overview of Receive Segment Coalescing
When receiving data, the miniport driver, NDIS, and TCP/IP must all look at each segment's header information separately. When large amounts of data are being received, this creates a large amount of overhead. Receive segment coalescing (RSC) reduces this overhead by coalescing a sequence of received segments and passing them to the host TCP/IP stack in one operation, so that NDIS and TCP/IP need only look at one header for the entire sequence.
RSC is intended to support coalescing in a way that:
Doesn't interfere with the normal operation of TCP's congestion and flow control mechanisms.
Coalesces packets without discarding information that is used by the TCP stack.
RSC-capable miniport drivers for network cards must:
Follow a standard set of rules when coalescing segments.
Provide certain out-of-band information to the host TCP/IP stack.
The following sections provide an overview of RSC.
- Rules for Coalescing TCP/IP Segments
- Updating the IP Headers for Coalesced Segments
- Examples of Receive Segment Coalescing
- Indicating Coalesced Segments
- Exception Conditions that Terminate Coalescing